This requires an implementation of the "text preparation algorithm" as
specified here:
html.spec.whatwg.org/multipage/canvas.html#text-preparation-algorithm
However, we're missing a lot of things such as the
CanvasTextDrawingStyles interface, so most of the algorithm was not
implemented. Additionally, we also are not able to use a LineBox like
the algorithm suggests, because our layouting infra is not up to the
task yet. The prepare_text function does nothing other than figuring out
the width of the given text and return glyphs with offsets at the
moment.
In the end this is a nicer API than having separate has_{value,target}()
and having to check those first, and then making another Optional from
the unwrapped value:
completion.has_value() ? completion.value() : Optional<Value> {}
// ^^^^^^^^^^^^^^^^^^
// Implicit creation of non-empty Optional<Value>
This way we need to unwrap the optional ourselves, but can easily pass
it to something else as well.
This is in anticipation of the AST using completions :^)
This means you can now do queries like:
```css
@media (400px <= width < 800px) { }
```
Chromium and Firefox which I tested with both don't support this yet, so
that's cool. :^)
Past me decided that the grammar was overly verbose and I could do it
better myself. Which seemed fine until the spec changed and I didn't
know how to integrate the changes. Lesson learned! :^)
Rather than have a function for every single part of the grammar, I have
written some as lambdas, and combned `<media-condition>` and
`<media-condition-without-or>` into one function. But otherwise it's
close to the spec, with comments listing the part of the grammar being
parsed, so hopefully it will be easier to make future adjustments!
This does not add any new functionality.
Web::CSS::MediaQuery::MediaFeature::Type was getting a bit ridiculous!
Also, this moves the detection of "min-" and "max-" media-features into
the MediaFeature itself, since this is an implementation detail, not
part of the spec.
Having these in here was a hack to support the other hack of making
media-queries use StyleValues. Now they don't do that, so we can remove
these again and keep things hygienic.
Previously, we were using StyleValues for this, which was a bit of a
hack and was brittle, breaking when I modified how custom properties
were parsed. This is better and also lets us limit the kinds of value
that can be used here, to match the spec.
This means we can get rid of the hacks where we were peeking a code
point instead of getting the next one so that we could peek_twin()
later. Now, we follow the spec more closely. :^)
This fixes the crash that Luke found using Domato:
```css
. foo {
mso-border-alt: solid .-1pt;
}
```
The spec distinguishes between "If the next 3 code points would
start..." and "If the input stream starts with..." but we were treating
them the same way, skipping the first code point in the process.
These correspond to "If the input stream starts with..." in the spec,
which up until now we were not handling correctly, which led to some fun
bugs.
As noted, reconsuming the input code point in order to read its value is
hacky, but works. Keeping track of the current code point in Tokenizer
would be nicer, when I'm feeling brave enough to mess with it!
This will allow us to easily add copies of the relevant canvas drawing
state to a stack, and likewise replace the current drawing state with
an entry from that stack.
I don't know if the original author simply missed this or thought the
default color of Gfx::Color is black, but this meant that drawing on a
canvas without explicitly setting a fillStyle or strokeStyle first would
be drawn in transparent color and therefore be invisible.
In the spec this is indicated by a small comment in the IDL definition:
attribute ... strokeStyle; // (default black)
attribute ... fillStyle; // (default black)
I'm starting to question whether Gfx::Color actually *should* have a
default constructor.
This wasn't quite following what the spec says for step 2:
"If index is −1, then remove the last element in the rows collection
from its parent, or do nothing if the rows collection is empty."
It was behaving like:
"If index is −1 and the rows collection is not empty, then remove the
last element in the rows collection from its parent."
Which is not the same, as it will fall into the "Otherwise" if
`index == -1` and the rows collection is empty and try and get the -2nd
element of the rows.
Found with Domato.
Step 1 of the spec is to capture the <script> element's node document
into a local variable.
When I originally implemented this, I thought this was not necessary.
However, I realised that the script that runs can adopt the current
script element into a different document, meaning step 5.4 and 6 then
operate on the incorrect document.
Covered by this WPT: 7b0ebaccc6/html/semantics/scripting-1/the-script-element/moving-between-documents-during-evaluation.html
This function initially returned a ByteBuffer, so `return {}` was fine.
It was then changed to return Optional<ByteBuffer>, so we accidentally
started returning an empty Optional instead. Explicitly specify the
constructor name to fix this.
Thanks to DexesTTP for catching this!
This is a simple implementation of SubtleCrypto.digest() using LibCrypto
under the hood, so it supports all the required hash functions:
SHA-1, SHA-256, SHA-384, SHA-512.
Two FIXMEs remain: doing the hashing "in parallel", and supporting an
object argument instead of a plain string.
Just some boilerplate code to get started :^)
This adds both the SubtleCrypto constructor to the window object, as
well as the crypto.subtle instance attribute.
This option is already enabled when building Lagom, so let's enable it
for the main build too. We will no longer be surprised by Lagom Clang
CI builds failing while everything compiles locally.
Furthermore, the stronger `-Wsuggest-override` warning is enabled in
this commit, which enforces the use of the `override` keyword in all
classes, not just those which already have some methods marked as
`override`. This works with both GCC and Clang.
Being really close to Object.prototype.valueOf() name wise makes this
unnecessarily confusing - while it sometimes serves as the
implementation of a valueOf() function, it's an abstraction which the
spec doesn't have.
Use the appropriate getters to retrieve specific internal slots instead,
most commonly [[FooData]] from the primitive wrapper objects.
For the Object class specifically, use the Value(Object*) ctor instead.
We now detect situations like this, where variables infinitely recur,
without crashing:
```css
div {
--a: var(--b);
--b: var(--a);
background: var(--a);
}
p {
--foo: var(--foo);
background: var(--foo);
}
```
We now stop processing variables once a length of 16384 tokens is
reached. This is an arbitrary number, but should be far beyond what
anyone will reasonably use, and small enough to not crash.
If a property is custom or contains a `var()` reference, it cannot be
parsed into a proper StyleValue immediately, so we store it as an
UnresolvedStyleValue until the property is compute. Then, at compute
time, we resolve them by expanding out any `var()` references, and
parsing the result.
The implementation here is very naive, and involves copying the
UnresolvedStyleValue's tree of StyleComponentValueRules while copying
the contents of any `var()`s it finds along the way. This is quite an
expensive operation to do every time that the style is computed.
